History of the Metric System Part 2 Non-Metric System

About the history of the metric system, the simple system of measurement the United States refuses to accept.

Meet the Meter

The metric system, like the U.S. currency, is a decimal system; all the units are related to each other by a factor of 10. Humans have used their 10 fingers to count on since the dawn of history, so the manipulation of units of 10 is almost 2nd nature. To convert from one metric unit to another, all one has to do is add easily memorized prefixes and shift the decimal point. For example, the prefix "centi" means one hundredth: c==1/100==10-2==0.01. "Milli" means one thousandth: m==1/1000==10-3==0.001. One millimeter is 1/1000 of a meter and 1/10 of a centimeter. "Kilo" means one thousand: k==1000==10 3. One thousand grams is one kilogram, which is approximately 2.2 lbs.; a thousand grams is also a liter in liquid measure, which corresponds roughly to one quart. Lists follow giving all the established prefixes and their equivalent values in nonmetric units; these have been prepared not only for weights and measures but for other physical quantities as well.

The nonmetric system and its shortcomings can be traced back to historical developments that took place before uniform reference standards could be established. For example, a medieval British ruler changed the Roman mile of 5,000' to 5,280' to make it conformable with the length of 8 furlongs. Another British king proclaimed that 3 kernels of grain--wheat or barley--laid end to end were the equivalent of one inch which, in turn, was 1/12 the length of a human foot. As a result we have remained saddled with a complicated system of units which have no relation to one another. There are troy ounces and avoirdupois ounces and liquid ounces. A quart of water has 57.75 cubic inches, but a quart of dry measure is equivalent to 67.20 cubic inches. Pricing or cost accounting of such irregular units using our decimal currency system is an unavoidably laborious process.

The only reason for the continued use of the nonmetric system is human inertia and an unwillingness to accept change. But, contrary to popular opinion, the metric system is already so well established in the U.S. that its official adoption does not constitute the introduction of a radically new system but merely the recognition of one which is already in use in many areas. For instance, we are used to 8-, 16-, or 35-millimeter film; doctors prescribe, pharmacists fill, and nurses administer medicine in cubic centimeter units. The consumption of electricity is measured in watts and kilowatts, and the engine displacement of automobiles is now commonly given in cubic centimeters. Spurred on by General Motors, Ford, IBM, Honeywell, and scores of other large companies who have announced their orderly conversion to the metric system, subcontractors, suppliers, and machine-tool manufacturers will increasingly work to metric standards. Presumably they will produce goods in nonmetric dimensions too, for some time to come, to satisfy the replacement market. But since that market will disappear in time, production eventually will be geared exclusively to metric standards.